Electrical contact.



E. E. CLEMENT. I I ELECTRICAL CONTACT. APPLIOATIQH nun s;rT.z9,-196.

Patented May 21, 1912.

EDWARD "E. cmmnn'r; or wasnineron. pisrmcr' '0F 'COLU 1\ !BiA.- l

nnnormcmi. common Tolall whom it may concern:

Be it known that'I, ED ARD CLEMENT, a citizen of the United States, residing at Washington, in the District of Columbia,

have invented certain new and useful Improvements in Electrical Contacts, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention relates to contact springs and the contact points thereof, especially to the latter and more especiall to contact points used upon the springs 0 relays and other spring switches. In the present use of such springs they are generally con platinum The excessive cost of platinum and the apparent lackot some'cheaper metal whichwould" perform .the same function hasled up to the present invention.

- The[invent1on consists in its simplest form of drawing a wire with a platinum of the wire as it is drawn before form-' coating thereupon into the requisite size then rolling the wire .at stated intervals so as to form constricted portions Where the interior metal is practically absent and Where the several enlarged portions between the constricted parts can be severed from one another. These portions with their then pointed ends are formed up into rivets as in Figure 3 whichare practically inexpensive as compared with the solid platinum rivets now emplo ed for this'purpose.

My invention is il ustrated in the accompanying drawings in which- Fig. 1 is a longitudinal sectional fragment ing. Fig. 2 i'sa longitudinal section of the wire after beingrolled or compressed. Fig. 3 showsa sectional view of therivet.

' Fig. 4 shows a side elevation of a contact spring with the rivet in position, and Fig.

5 is a top plan view thereof.

In Fig. 1 I show a section of a piece of .Wire 1 of any suitable material such as German silver, silver or copper which is coated, plated or has drawn thereon a covering of platinum 2. The wire is then rolled or compressed at points, marked 3 in any suitable .inanner to form constricted portions where the base metal 1 is practically absent. This process ofqcourse forces the of base metal, a coating of non-oxidizabl'e Patented Maya, 1912.

the wire and somewhat increasesits lateral dimensions thereat. The enlarged portions 4 now being'separated by the constricted portions 3 are then cut off upon the dotted linesrF-w and each separate piece is then formed up as shown in Fig. 3, whereby a base metal; into the enlarged portions 4 of head 5 and a shank portion 6 is forined'with the base metal 1 inside and the platinum coating 2 upon the outside. This forming also compresses one end of the piece as at i 7 to form practically a solid platinum point, the metal from within being squeezed or compressed into the shank 6 and the head 5. The rivet is'now. passed through an aperture 8 in one end of the'spring 9 and the extended portion 7v is flattened out to 'form the disk contact 10 which forms the mate for the pointed head contact 5.

It will be seen from this construction that very little platinum-is used andthat the cost of the rivet is thereby greatly reduced, thus enabling relays or other switching dcvices to be manufactured at little cost as compared with the now rather expensive mode of construction. It will also be seen that I mayuse any sort ofmeta'l suitable for a body and that I may also coat-or cover as. v

the body of basemetal in'any suitable manl ner such as plating, rolling or inserting the body within. a tube ofplatinum and then drawing both together. All such modificae tions are considered to be within the scope and purview of the appended claims.

.Having thus described my invention what Y I claim and desire to secure by Letters Pat- -ent is:

1; A. rivet comprising a body of base metal,a coating of non-oxidizable metal, and a rivet extension formed of the latter metal. Y

2. A rivet comprising a head and a shank metal therefor, and acontinuation of the shank formed of said latter metal.

head.

4. The process of tipping electrical coninto close contact with said springs and with tact springs With "precious metal-w,hich conthe precious metal exposed. sists of Welding a surface layer of said pre- In testimony whereof I afiix my signature cious metal upon a body of baser metal, cut- 'in presence of two witnesses.

-'- ting said bimetallic body into cylinders EDWARD E. CLEMENT.

tipped with said precious metal, inserting Witnesssz' said cylinders into holes in the electrical. JAMES H. MARK, contact springs and riveting said cylinders E. EDMONSDON, Jr. 

